Reversibly reducible cis-dichloroplatinum(II) and cis-dichloropalladium(II) complexes of bis(1-methylimidazol-2-yl)glyoxal
| Autor: | Tereza Varnali, Ece Bulak, Orkan Sarper, Falk Lissner, Jan Fiedler, Brigitte Schwederski, Markus Leboschka, Wolfgang Kaim, Thomas Schleid |
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| Rok vydání: | 2007 |
| Předmět: |
Models
Molecular Organoplatinum Compounds Chemistry Ligand Cyclohexane conformation Molecular Conformation Glyoxal Photochemistry Crystallography X-Ray law.invention Inorganic Chemistry Metal chemistry.chemical_compound Crystallography law Spectrophotometry visual_art visual_art.visual_art_medium Electrochemistry Platinum Compound Imidazole Density functional theory Physical and Theoretical Chemistry Electron paramagnetic resonance |
| Zdroj: | Inorganic chemistry. 46(14) |
| ISSN: | 0020-1669 |
| Popis: | Complexes cis-MCI 2 (big), big = bis(1-methylimidazol-2-yl)glyoxal, M = Pt, Pd, were prepared and characterized through electrochemistry, spectroscopy, and for M = Pt, by X-ray structure analysis. The seven-membered chelate ring formed through N,N' coordination of the ligand big shows a boat conformation in agreement with density functional theory (DFT) calculation results. No significant intermolecular interactions were observed for the platinum compound. Both the Pd" and Pt" complexes undergo reversible one-electron reduction in CH 2 Cl 2 / 0.1 M Bu 4 NPF 6 ; the reduced palladium compound disintegrates above -30 °C. Electron paramagnetic resonance (EPR), UV-vis, and IR spectroelectrochemistry studies were employed to study the monoanions. The anion radical complex [cis-PtCl 2 (big)] exhibits a well-resolved EPR spectrum with small but well-detectable g anisotropy and an isotropic 195 Pt hyperfine coupling of 12.2 G. DFT calculations confirm the spin concentration in the α-semidione part of the radical complex with small delocalization to the bis(imidazolyl)metal section. The results show that EPR and electroactive moieties can be linked to the cis-dichloroplatinum (ll) group via imidazole coordination. |
| Databáze: | OpenAIRE |
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